Pipe connecting piece and pipe connection obtained by means thereof

ABSTRACT

A pipe connection comprising a corrugated pipe connection piece of thermoplastic material, and two male pipe parts, the pipe connection piece being provided with four crests and a narrowing smaller than the inner diameter of the connection piece being situated symmetrically with respect to the crests. A rubber sealing ring is maintained in a crest by means of a maintaining ring cooperating clampingly with a wave valley of the connection piece.

United States Patent 1 1 de Putter Mar. 12, 1974 PIPE CONNECTING PIECEAND PIPE 3,596,939 8/1971 Gibson 285/369 CONNECTION OBTAINED BY MEANS3,368,830 2/1968 French 285/235 X 2,049,801 8/[936 Gage 285/383 THEREOF3,516,693 6/1930 Glover 285/235 [75] Inventor: Warner Jan de Putter,Hardenberg, 1,819,007 it 1 1. 285/383 X Netherlands 3,632,141 1/1972Larsson 285/383 x [73] Assignee: IlullustielenonltillerrlienrngdWavinPrimary Examiner Mervin Stein W0 at er an 5 Assistant ExaminerDavid H.Corbin [22] Filed: Oct.2l, 1971 Attorney, Agent, or Firni-Whitternore,Hulbert & 211 App]. No.2 191,400 Beklnap 57 ABSTRACT [52] US. Cl285/235, 285/345, 285/379, 1

- 285/D|G 4 A plpe connection compr1s1ng a corrugated p1pe con- 51 111c]. Fl6l 21/04 necticm Piace 0f thermoplastic material, and two male[58] Field 61 Search 285/223, 226, 229, 235, P9115, the Pipe beingProvided 285/345, 369 379 383, D164 with four crests and a narrowingsmaller than the 1 v a inner diameter of the connection piece beingsituated [56] ReferencS Cited symmetrically with respect to the crests.A rubber UNITED STATES PATENTS sealing ring is maintained in'a crest bymeans of a maintaining ring cooperating clampingly with a wave 3glgllneruk 285/235 X valley of the connectign piece C un 1329.23610/1931 Perkins 285/229 I 1 Claim, 4 Drawing Figures 7 1a 12 13 12 1 l11 1 9 17 1o 10a l 1 1 1 1 1 1 1 1 16a 2 16 1881i 5111 PIPE CONNECTINGPIECE AND PIPE CONNECTION OBTAINED BY MEANS THEREOF BACKGROUND OF THEINVENTION The invention relates to a pipe connecting piece ofthermoplastic synthetic material with tranverse waves which is resistantto deformations up to heating temperatures of at least 20 C below thelowest possible extrusion temperature of the thermoplastic syntheticmaterial.

Pipe pieces of thermoplastic material with transverse corrugations arecommonly known, such pipe pieces are obtained by subjecting extrudedthermoplastic pipes, directly after their extrusion, to a deformation,whilst enclosing them by dies provided with transverse grooves andwhilst applying an inner overpressure in the thermoplastic pipe withrespect to the ambient pressure. Due to their deformation directly afterthe extrusion these pipe pieces are resistant to deformation up toheating temperature of at least 20 C below the lowest possible extrusiontemperature of the thermoplastic synthetic material.

Such pipe pieces are applied when electric ,leads should be laid inbuildings or houses, while in the last few years such pipe pieces ofthermoplastic material with transverse corrugations aremuch used in thefield of draining and/or irrigation.

Due to the provision of openings in the thermoplastic pipes particularlyin the grooves situated between the transverse corrugations such pipepieces can namely be used for transferring drained off water or forfeeding irrigation water to dry ground, while then.through these pipetubes water is fed which issues through the afore mentioned openings.

It has been found that such pipes pieces of thermoplastic material withtransverse corrugations is particularly suitable to be used as pipeconnecting pieces instead of the so far applied connecting pieces in theshape of plastic sockets. Such an application is very advantageous,since to so far applied pipe connecting pieces in the shape of plasticsockets should be manufactured by injection moulding, which due to theconsiderable thickness of wall gives rise to rather high costs ofproduction, while pipe pieces of thermoplastic material with transversecorrugations can be produced in a very simple way and less material isrequired for the same strength from which results a considerable economyon material.

SUMMARY OF THE INVENTION It is now an object of the invention to providea pipe connecting piece of thermoplastic material with transversecorrugations which is resistant to heating temperatures of at least 20 Cbelow the lowest possible extrusion temperature of the thermoplasticmaterial and wherein the pipe piece, comprises at least two transversecrests at both sides of a narrowing, situated between the transversecrests serving to, accommodate sealing means, the inner diameter ofthese narrowing being smaller than the inner diameter of the rest of thepipe piece. The narrowing is preferably symmetrically situated inbetween four transverse crests.

Since in such pipe pieces the transverse crests may serve' toaccommodate the sealing means and on the other hand it is possible toprovide in a rather simple way--in manufacturing such pipe pieces thedies used therefor with inwards directed projections it is possibletomanufacture in an inexpensive way pipe pieces with transverse crestsand the desired narrowing which are well adapted to be applied to a pipeconnection.

The pipe connecting pieces according to the invention are preferablymanufactured from polyvinylchloride or polyethylene. It is, however,also possible to use polypropylene for such pipe connections. Thenarrowing is efficiently formed by a wave valley between two transversecrests the lower points of which are within the cylinder constituted bythe inner wall of the other wave valleys.

1 By using such pipe part it is possible to obtain a pipe connectioncomprising at least a male pipe part and a pipe connecting piece forreceiving a male pipe part. This pipe connecting piece is provided witha narrowing between two crests situated on either side of the narrowing,while sealing means are accommodated in these grooves.

Another important advantage of a pipe connection according to theinvention consists in that due to application of a pipe piece accordingto the invention less material than so far is required for the pipeconnecting piece, since due to the application. of transverse crests therigidity pipe piece is improved in such a way that it is resistant to ahigher load than pipe connecting pieces without transverse crests.

According to a preferred embodiment of a pipe connection the innerdiameter from the transverse crest situated at the free end is alwaysgreater than the smallest inner diameter in the vicinity of the free endwhich mostly corresponds with the inner diameter of the pipe at thelocation of the end of the pipe or the wave valley which is at the endof the pipe piece.

Preferably the connecting parts between the transverse crests aresituated on a conical surface the generatrix of which extends betweenthe top of the transverse crests, situated beside the narrowing, and thepoint at which the inner diameter in the proximity of the free end issmallest.

Such a pipe connecting piece enables the male pipe part to movepivotally and to absorb movements produced in the ground owing to theslipping of a mass of land without causing damage to the pipe connectingpiece according to the invention.

SUMMARY OF THE DRAWINGS:

The invention will now be clarified with reference to the drawing inwhich an embodiment is represented.

In the drawing:

FIG. 1 is a section of a pipe connection with pipe piece according tothe invention, and

FIG. 2 is a pipe from which pipe connecting pieces with transverse wavesfor application to a pipe connection are manufactured;

FIG. 3 is another embodiment of a pipe connecting piece according to theinvention, and

FIG. 4 is a special variant of such a pipe connecting piece according tothe invention, with male pipe part.

DESCRIPTION OF PREFERRED EMBODIMENTS ln FIG. 1 is represented a pipepiec'el made of polyvinylchloride with transverse crests 2, 2a, 2b andv20. Instead of four transverse crests 22c only two transverse waves towit the transverse waves 2a and 2b suffice. This pipe piece is resistantto deformation or heating temperatures of at least 160 C that is to sayat least 20 C under the lowest possible extrusion temperature of thisthermoplastic material. This resistance to deformation results from thefact that these pipe pieces are obtained by extruding a pipe ofthermoplastic material in the shape of polyvinylchloride and guidingsame immediately between a mould, moving along with the pipe, andgenerating in the pipe an inner over pressure with respect to theambient pressure, whereby the plastic pipe is pressed against thegrooves in the mould. In this way a pipe of the pipe as represented inFIG. 2 is obtained. By sawing through such a pipe at the point 4 a pipeconnecting piece like represented in FIG. 1 is obtained.

Between the transverse crests 2b and 2a is a wave valley 5 the lowerpoint 5a of which is situated within the cylinder 6 constituted by thelower points of the other wavevalleys 7a, 7b, 7c, 7d in pipe piece 1.

Due to the selection of the lower point of the wave valley 5 anarrowing, which can also be denoted by 4, is also obtained within thepipe piece 1.

The narrowing 4 is symmetrically situated between the transverse crests2, 2a, 2b and 2c serving to receive sealing means 8 in the shape ofrubber rings or rubber sealings. In the embodiments shown the sealingmeans 8 are accommodated in the recesses constituted by the transversecrests 2, 20, but it will be obvious that the aforementioned means couldalso be accommodated in the recesses constituted by the transversecrests 2a, 2b. This is, however, less advisable, since hereby the sealing means come close to lie at the end 9 of the male pipe part 18 and18a. This pipe part is smooth.

If desired sealing means may be accommodated in the recesses formed bythe transverse grooves 2, 2a, 2b, as well as 2c. The narrowing 4 whichin FIG. 1 is represented as a deepened wave valley can also be formed byexerting a compressive force at the ends of pipe piece and as shown inFIG. 3 to slide into the pipe piece an annular ring member 19 with anouter diameter such that on cancelling the compressive force to whichthis pipe piece is subjected the ring 19 clampingly contacts the lowestpoint 90 of the wave valley 9 which is then as deep as the wave valleysituated between the transverse crests 2b and 2c and between 2a and 2.It will, however, be obvious that an additional treatment is requiredtherefor. In this way it is, however, also possible, starting from thecommercially available pieces of plastic pipe with transverse crests, tomanufacture directly a pipe piece according to the invention which issuitable for the pipe connection.

In FIG. 4 is represented a pipe connecting piece com prising threetransverse crests on either side of a narrowing 24 constituted by a wavevalley. The transverse waves are denoted by the references ll, l2, l3and 11a, 12a, 13a, respectively. The sealing means 28, 28a areaccommodated in the transverse crests 13, 13a, respectively, the sealingmeans consisting e. g., of a rubber ring maintained by a ring 20inserted between wave valley l0 and pipe part 18.

" 5 In the vicinity of the free end 17, 19a of the pipe connecting pieceis a wave valley 10, 10a, respectively, while at that location the innerdiameter is larger than the smaller inner diameter at the location ofthe narrowing 24, but on the other hand this inner diameter is smallerthan the inner diameter of the other part of the pipe connecting piecesituated between the narrowing 24 and the end 17. The transverse waves11, 12, 13 and 11a, 12a, respectively are connected by connecting pieces14, 15 and 14a, 15a, respectively which are situated on a conicalsurface the generatrix of which corresponds with the line drawn throughthe connecting parts 14 and 15. In this way a space 16, 16a,respectively is obtained in which the male part situated in the pipeconnecting piece can pivot about 17, 170.

In order to avoid removal of ring 8 accommodated in the crest 20 duringinsertion of pipe part 18, it is recommended to maintain said ring asshown in FIGS. 3 and 4 by means of a maintining ring 20 which cooperatesclampingly with the bottom of a wave valley. The sealing means, may nowconsist of a ring body 22 having a lip 21 cooperating with pipe part 23as shown in FIG. 3 or sealing rings 28,2 8a with lips 31,3la as shown inFIG. 4.

The maintaining ring 20 consists of a relatively thin walled plasticmaterial which can be inserted by deformation. It is even possible toimprove the flexibility of the maintaining ring by providing the ring 20with longitudinal notches ending before the end of the ring c0-operating with the sealing means and starting from the opposite end.

What I claim is:

l. A pipe connection adapted to surround the spaced adjacent ends of twocylindrical pipes, said pipe connection being a thin-walled corrugatedsleeve having a central inwardly directed wave valley of smallerdiameter than said pipes extending into the space between said adjacentpipe ends, said corrugated sleeve having at its opposite ends inwardlydirected wave valleys substantially engaging the respective pipes, andhaving intermediate portions between said central and end wave valleyswhich are of larger diameter than said pipes providing a substantialclearance space into which the pipe ends can be laterally displaced bypivoting about the points where said inwardly directed end wave valleyssubstantially engage said pipes, each intermediate portion having threetransverse crests extending outwardly from-a conical surface, thegeneratrix of which extends between the transverse crest adjacent saidcentral wave valley and the point at which the inwardly directed endwave valley substantially engages said pipe, the outer of saidtransverse crests receiving a sealing ring which is maintained thereinby means of a thinwalled plastic ring cooperating clampingly with thebottom of said end wave valley, said sealing ring having a lip extendingbeneath the bottom of a wave valley, said wave valleys and said crestsextending circumferentially around said sleeve and said conical surfaceextending radially outwardly from said crests receiving said sealingring.

1. A pipe connection adapted to surround the spaced adjacent ends of twocylindrical pipes, said pipe connection being a thinwalled corrugatedsleeve having a central inwardly directed wave valley of smallerdiameter than said pipes extending into the space between said adjacentpipe ends, said corrugated sleeve having at its opposite ends inwardlydirected wave valleys substantially engaging the respective pipes, andhaving intermediate portions between said central and end wave valleyswhich are of larger diameter than said pipes providing a substantialclearance space into which the pipe ends can be laterally displaced bypivoting about the points where said inwardly directed end wave valleyssubstantially engage said pipes, each intermediate portion having threetransverse crests extending outwardly from a conical surface, thegeneratrix of which extends between the transverse crest adjacent saidcentral wave valley and the point at which the inwardly directed endwave valley substantially engages said pipe, the outer of saidtransverse crests receiving a sealing ring which is maintained thereinby means of a thin-walled plastic ring cooperating clampingly with thebottom of said end wave valley, said sealing ring having a lip extendingbeneath the bottom of a wave valley, said wave valleys and said crestsextending circumferentially around said sleeve and said conical surfaceextending radially outwardly from said crests receiving said sealingring.